[ns] problem with creating a new agent

[sashtari]

Hi every body

I want to create a new agent completely similar to a UDP agent.
I've copied udp.cc and udp.h, then renamed them to my agent, added my
agent to Makefile and modify ns-default.tcl. Finally I've recompile NS2
(configure and make,....).
But when I want to attach this new agent to a node in tcl, I have some
errors:
    (_o3 cmd line 1)
    invoked from within
"_o3 cmd attch-agent _o10 _o114"
    invoked from within
"catch "$self cmd $args" ret"
    invoked from within
"if [catch "$self cmd $args" ret] {
set cls [$self info class]
global errorInfo
set savedInfo $errorInfo
error "error when calling class $cls: $args" $..."
    (procedure "_o3" line 2)
    (SplitObject unknown line 2)
    invoked from within
"$ns attch-agent $n0 $lldp0"

Do you know which other file(s) should be modified?

Thanks
Saeideh